The Australian man at the centre of the Thai surrogate abandoned baby row is facing allegations that he served a prison sentence for multiple convictions for sexual offences against children.

The couple have faced a fierce backlash after apparently refusing to take the six-month-old boy, named Gammy, from his Thai surrogate mother because he has Down’s Syndrome and a congenital heart condition - only accepting his healthy twin sister.

According to media reports from the time, the West Australian electrician, who was then 39, pleaded guilty to the sex crimes and had previously admitted to molesting two teenage girls 15 years earlier.

In the newspaper article, Judge Michael O’Sullivan said his actions had violated the youngsters’ innocence and warranted a jail term.

Australia’s Channel Nine reported that that the wife, who is of Asian origin, knew about her husband’s conviction but insisted he was “a good man”.

The judge said the father would normally receive four years for his crimes but instead would be sentenced to three years because of his early guilty plea.

The revelations come as a friend of the couple accused of abandoning baby Gammy spoke out on behalf of the "devastated" pair, saying many statements made by the surrogate mother have been lies.

Speaking to the Bunbury Mail newspaper, the unnamed friend of the couple says the parents are legally unable to speak, but were distressed by reports they did not want to bring the little boy home.

The friend said the couple were told baby Gammy had a congenital heart condition and would “not survive a day”.

The plight of baby Gammy was already hugely controversial before the new allegations surfaced about the husband and has prompted Australia’s government to consider reforming surrogacy services in the country.

Pattaramon Chanbua, 21, was reportedly paid $15,000 (£9,000) to be a surrogate for the unidentified Australian couple.

Mrs Pattaramon was told of the child's condition four months after becoming pregnant and the couple asked her to have an abortion but she refused, saying it was against her Buddhist beliefs.

Ms Pattaramon, who already has two children, says she cannot afford to pay for the Gammy’s medical costs but that she wants to "take care of Gammy" as her own.